So I know how to say "I went to eat at a Japanese restaurant with Tanaka yesterday." たなかさんと昨日に日本のレストランでたべました。And I also know how to say "The Japanese restaurant is to the next to the movie theater." 日本のレストランは映画館のとなりにあります。

Now, how would I say, "I went to eat at a Japnese restaurant next to the movie theater with Tanaka yesterday."?

I think 和食屋さん or 日本料理屋さん sounds better for Japanese restaurant in another country. I believe レストラン usually applies to eateries that serve western-style foods and a Japanese restaurant in Japan would generally be called by the kind of food that they serve ie: うどん屋さん、寿司屋さん、ラーメン屋さん etc.

Thank you guys for the explanation. Sairana, initially I knew that I had to modify the phrase into a noun to make the sentence works. However I wasn't sure if I needed a specific marker after the word ある. As for using "たべました" I didn't know that Japanese has a specific way of saying "I went to eat". So together in one long sentence as richvh pointed out, the sentence would be 昨日、田中さんと一緒に映画館のとなりにある日本料理レストランで食べに行きました。Correct? Now when I want to say I'm doing so and so with someone or a group of people, do I really need to use 緒に or is it perfectly find to omit it?

For a long sentence like this, I know that it is probably better to use ある than あります. However I want to know if the overall politeness tone has been changed with ある or if it is even grammatically correct to use あります instead?

amaravati wrote:For a long sentence like this, I know that it is probably better to use ある than あります. However I want to know if the overall politeness tone has been changed with ある or if it is even grammatically correct to use あります instead?

It's very common even in polite(as in everyday) Japanese to just use the casual forms of verbs and adjectives all the way through the sentences until they get terminated which is where the masu/desu forms come into the picture. The only reason I could see anyone saying あります in a clause like that would be to be extremely polite.